Showcasing Emerging Green Innovations and Ideas

The wings of the butterfly Pachliopta aristolochiae, or Indian Common Rose, absorb just about all of the light that falls on them. (Wikimedia Commons)

By: Bob McDonald

The black wings of a butterfly have provided a simple way to improve the light gathering abilities of solar cells. It is the latest example of how science turns to nature to find elegant solutions to technical problems.

Solar cells are a wonderfully clean way to turn sunlight directly into electricity with no moving parts and no pollution. But since their current invention more than 60 years ago, they have suffered from inefficiency. Early versions only converted about 1 to 2 per cent of the sunlight falling upon them. That has been improved to roughly 20 per cent today, but that still means 80 per cent of the sunlight is not being used.

Part of the problem is that solar cells tend to have smooth surfaces, which act as partial mirrors, reflecting sunlight back into the sky rather than absorbing it. It was in an attempt to make the surface of solar cells less reflective, and therefore absorb more light, where the scientists turned to the butterfly.

Solar cells are a wonderfully clean way to turn sunlight directly into electricity, but they’ve suffered from inefficiency. (J. Pat Carter/Associated Press)

The wings of the butterfly Pachliopta aristolochiae, or Indian Common Rose, are a very dark black. This means they absorb just about all of the light that falls on them. (Total reflection of light produces white.) Scientists from Karisruhe Institute of Technology report in the journal Science that under a powerful microscope, they saw tiny holes in the butterfly wings known as nano structures. These little structures, invisible to the naked eye, come in different sizes and shapes, something like the surface of a sponge.

Light-absorbing wings

The holes allow light to penetrate deeper into the wing, increasing the surface area so more light is absorbed without making the wings larger. And the different sizes of holes enable the butterflies to absorb all the colours of light that fall on them, resulting in their deep black colour.

For the butterfly, their light-absorbing wings are used for temperature control. For the scientists, they wanted to apply the same technique to solar cells, so more light could be turned into electricity.

Swiss engineer George de Mestral is the inventor of Velcro, inspired by the many burrs fastened to his pants and his dog’s fur after a hike. (Nano Vivid)

After examining these natural structures under an electron microscope, the scientists reproduced a similar pattern onto the surface of a thin film solar cell. It is made of a modern flexible material that is usually used in smaller applications. When they shone light straight down on the surface, absorption increased by 97 per cent. That number shot up to 207 per cent when the light beamed down at an angle, which is important for solar panels, which are not always facing directly at the sun.

It seems that the little holes act as caves, letting the light penetrate deeper into the surface and be absorbed along the cave walls.

This could become a tremendous step forward to improving the efficiency of this type of solar panel and making them more competitive in the alternative energy market.

Seeds inspire Velco invention

This is not the first time nature has inspired science, often leading to useful inventions. In the 1940s, Swiss inventor George de Mestral was walking his dog and noticed seeds that had attached themselves very strongly to the dog’s fur and his pant legs. When he examined the seeds closely, he saw a miniature hook system that grabbed onto loops in fabric and fur. The result was one of our most useful sticky materials: Velcro.

Materials scientists are very interested in gecko feet not just because they stick to almost any surface, but they also instantly let go on demand. (L. Lee Grismer/WWF)

NASA also looked to nature when it developed robots that resemble insectswith legs instead of wheels to explore other planets. That’s because walking is better for covering uneven terrain.

And then there is the gecko, a small lizard with the amazing ability to climb walls, cling to the ceiling and even stick to smooth surfaces such as a mirror. The secret, discovered under a microscope, is a large number of tiny hairs that increase the footpads contact area with the surface. They use what are known as van der Waals forces, which are very weak and only act at microscopic distances, but add up when surface contact is very large.

Materials scientists are very interested in gecko feet not just because they stick to almost any surface, but they also instantly let go on demand, leaving no residue, allowing the gecko to run. A tape with that ability would be very valuable, and gloves made of gecko-like material would allow people to climb walls.

It makes sense that nature can show us better ways to do things. After all, it has had millions of years to experiment and evolve the best solutions to problems such as sticking to a surface, absorbing light, flying, swimming, seeing in the dark and countless other adaptations that have allowed animals and plants to survive in different environments.

In the case of solar cells, nature has shown us how to manage energy more efficiently, which is a lesson we we need to learn in so many other systems as well.

The Trump strategy of slapping penalties on these technologies and giving fossil fuels subsidies has a very limited shelf life

By: Juan Cole

From Scotland to Sweden, nations around the world and experimenting with renewable energy technology, including solar panels and wind turbines. (Photo: Shutterstock)

Wind and solar keep falling in price—each fell 6 percent in 2016. That fall was not as big as the two previous years, but there is every reason to expect price drops much bigger in coming years, as new technology makes the move from basic science to implementation. The Trump strategy of slapping penalties on these technologies and giving fossil fuels subsidies has a very limited shelf life, since there aren’t enough resources in the world to stand against this kind of inexorable progress.

Wind turbines in Scotland during the month of October, driven by unusually strong gales, generated enough electricity to supply 99 percent of the country’s power needs, taking into account residential, industrial, and business sectors! And if we just looked at the residential market, the wind turbines could have powered 4.5 million homes! One catch: Scotland only has about 2.45 million households!

On average through the year, Scotland now gets 60 percent of its electricity from renewables and is on track to get 100 percent from green sources by 2020. One impediment standing in the way is that the English-dominated government of the U.K. is deeply tied to BP and other fossil fuel companies and keeps trying to hobble green energy. In the U.K. as a whole, green energy only produces 29 percent of electricity.

And then there is Sweden. GE and Green Investment Group have raised some $900 million. for the largest onshore wind farm in Europe. To be built in northern Sweden, it will have a name plate capacity of 650 megawatts and will be operational in only two years. With increasingly inexpensive battery storage or e.g., hydropump storage, such wind farms could generate up to half as much steady electricity as a small nuclear reactor. (Toshiba is putting in huge battery storage near a major wind farm in Texas.)

In Sweden, this one wind farm will increase the country’s wind power by 12.5 percent. Sweden is already a relatively low-carbon country for an industrial economy, though it can do substantially better. Some 83 percent of the country’s electricity comes from nuclear and hydroelectric power. Only 7 percent comes from wind at the moment.

Still, the average Swede emits over 4 tons of carbon dioxide a year. That is better than Europe’s average 6 tons and “way better than the U.S. average of 16 tons per year per person(!!!). But 4 tons a person is still huge, given that CO2 is like setting off atomic bombs in the atmosphere. The new Markbygden ETT wind farm will be an important step toward carbon-free Swedish electricity. Of course, that has to be combined with switching to electric vehicles and adopting low-carbon agricultural and building techniques if we are to move to a net carbon zero civilization.

The world is shifting from fossil fuels to renewable energy in a big way right now, but a group of scientists has come up with a new kind of material that works like a renewable substitute for coal.

This ‘instant coal’ biofuel brings the high energy efficiency of coal without the usual damaging side-effects – such as deep mining to collect it, and resulting pollution from burning it and releasing impurities.

What’s more, it doesn’t take eons to form underground, and is instead made from agricultural waste including wood and plants. That means we’ve potentially got a never-ending source of the stuff, according to the team developing it at the Natural Resources Research Institute (NRRI), part of the University of Minnesota Duluth.

“If you think about how Mother Nature made fossil coal, it’s time, pressure and heat,” says one of the team at NRRI, Tim Hagen.

“We’re doing those same processes, but instead of millions of years, we’re doing it in a few hours. And because minerals don’t get into the mix, we don’t have those potential pollutants.”

The BTU or British Thermal Unit is an indicator of stored energy: coal offers around 12,500 BTUs per pound, but this new biofuel is right up there with 8,000 to 9,500 BTUs per pound. A different variation, known as energy mud, can hit even higher levels.

These biofuel briquettes are produced using a process similar to coffee roasting, where raw biomass is dried and then heated up to 249°C (480°F) in a low-oxygen atmosphere, before being compressed. Technically it’s known as torrefaction.

“Maybe you like light roast coffee, it’s not as concentrated… or you can take it further and have a dark roast coffee. We can do the same thing here,” says one of the NRRI researchers, Don Fosnacht.

Meanwhile, the energy mud is made through an alternative system akin to a pressure cooker. Known as hydrothermal carbonisation, it removes the drying stage of the process. Between the two techniques, the Renewable Energy Lab is producing between four and six tons of biofuel a day.

It’s going to be some time before this ‘instant coal’ is ready for widespread and commercial use, but potentially it could reduce emissions from coal-fired power plants, power steam engines, reduce our reliance on mining coal for making steel and other iron products, and utilise natural waste from plants and trees at the same time.

As an added bonus these materials are easy to transport – they repel water and don’t rot.

Reducing our reliance on coal and fossil fuels can’t happen soon enough, with carbon dioxide levels in the atmosphere now the highest they’ve been for some 3 million years. That in turn is driving temperatures up and up.

The Renewable Energy Lab is now busy looking for commercial partners to help them scale up the process of making their coal substitutes. We’re hoping the world’s industries can make use of it sooner rather than later.

The solar compass at Thompson Rivers University, as seen from above. BC Sustainable Energy Association photo

It may look like a compass, but the solar installation at Thompson Rivers University is designed to do more.

Ultimately, said Michael Mehta, it could point the way to integrating charging strips in roadways that could charge electric vehicles as they are being driven.

For now, however, the solar compass outside the Arts and Education Building on campus has other purposes, said Mehta, a geography and environmental-studies professor at TRU.

First, it’s to demonstrate how solar can be commonplace and not relegated to large panels on tops of buildings or out in fields. It’s also designed to show solar projects can also look good.

Mehta entered the project into the university’s sustainability grant competition. Once approved, he opted to use the existing compass design at the building, but build into it more than five dozen one-foot by two-foot solar modules, each producing 80 watts of power that ultimately should see it generate enough power per year to run about 40 computers and printers.

Just prior to the official unveiling of the compass on Thursday, with the city experiencing its first significant snowstorm of the season, Mehta kept an eye on the installation to see how people reacted walking on it. He didn’t expect to see a flurry of falls, he said, because the only real difference people might feel walking on it is the modules have a slightly different friction level than the sidewalks surrounding them.

He likened it to walking on a sidewalk and encountering a painted line or a grate. There’s a different feel underfoot, but nothing too significant.

The compass has been in place and generating energy since July, so students are likely familiar with its underfoot feel, he said.

The solar walkway is a first in Canada. The university invested about $30,000 in the project, which Mehta and other researchers will continue to monitor.

The panels were donated to the university by Solar Earth Technologies.

Citizens’ Assembly hears how Denmark became one of most efficient countries in world

Image: futurism.com

By: Ronan McGreevy

Scotland is on target to generate all of its electricity from renewable sources by 2020, the Citizens’ Assembly has heard.

Under chair Ms Justice Mary Laffoy, the 99 assembly members, meeting in Malahide, Co Dublin are spending a second weekend debating on how the State can make Ireland a leader in tackling climate change.

Scotland has hit its 2020 emission targets five years early and has gone from delivering 10 per cent to 60 per cent of its electricity consumption from renewable sources over the past 15 years.

Prof Andy Kerr told the assembly members that the Scottish Assembly had set the most ambitious renewable targets possible. Instead of the UK goal of having CO2 emissions 32 per cent lower than they were in 1990, the Scottish Nationalist Party (SNP) set a target of 42 per cent.

The switch to renewables has been achieved without a detrimental impact on the Scottish economy and there is no longer a choice to be made between the environment and the economy, he said.

Prof Kerr said Scotland’s “enviable reputation” on the issue of climate change has been achieved with cross-party support. The Scottish Assembly voted unanimously in 2009 for the higher target of a 42 per cent reduction in CO2 levels by 2020 – from 1990 levels, and 80 per cent by 2020.

It was also achieved with the support of some of Scottish biggest industries including the whiskey industry.

The general public have also been broadly in support with recent surveys indicating that 75 per cent of the population are in support of measures to curb climate change.

He also said Scotland had been clever in dealing with objectors to wind farms with grants to local communities which allowed them to take an equity share in developments.

The Scottish government set a target for 500MW of locally owned energy generation facilities across Scotland by 2020, but has already exceeded this. It is resetting this target at 1,000MW (1GW) of installed capacity.

“There is clear evidence in Scotland that supporting local communities to get involved in – and benefit from – the local energy system enables a range of related social and economic co-benefits,” he said.

Prof Kerr said climate change was not pitched as being “about polar bears” but about a more sustainable way of life into the future.

Denmark

Former European commissioner for climate change Connie Hedegaard said her native Denmark was now, along with Japan, the most energy efficient country in the world.

Half of Denmark’s electricity is now generated from renewable energy sources. Since 1990, the CO2 intensity of Danish industry has dropped by more than half and the energy intensity (the amount of energy consumed by Danish industry) is down by a third.

Thirty per cent of all energy consumed in Denmark now comes from renewable energy sources.

Ms Hedegaard said the presumption that renewable energy sources would be more expensive than oil or gas has not come to pass.

Energy prices in Denmark are around the average in Europe both for industries and householders.

In addition, 60,000 jobs have been created in Denmark in clean tech companies, a significant number in a country of five million people, she said.

Ms Hedegaard, who is also a former Danish minister for climate, said taxation was crucial in changing behaviour.

She said the one thing that Ireland could learn from the Danish experience was ensuring that successive governments of whatever political persuasion should continue to implement a policy of climate change.